fixing duplicate services that are seperate only by casing

[flipyap]

One problem we've experienced is that when you register a service in consul it is case sensitive. so for example, registering
redis and REDIS will register 2 services. However the "gotcha" is that instances of EITHER service will tie to BOTH services.

example:

redis service
-------------
instance-1-redis
instance 2-redis
instance-1-REDIS
instance-2-REDIS

REDIS service
-------------
instance-1-REDIS
instance-2-REDIS
instance-1-redis
instance 2-redis

This creates duplicate metric entries for consul_service_tag and consul_node_healthy metrics when in reality it shouldn't fail on this. I do say i mostly blame consul for the way its done, but from what i know it was done like that on purpose because that is how the DNS is going to work with consul (case INSENSITIVE).

This simple check looks to make sure the entry/instance (instance-2-REDIS) and its service name matches the service that we are looking up (REDIS service) aka /v1/health/service/REDIS. if the instance doesn't match (instance 2-redis) we skip it.

[flipyap]

@simonpasquier let me know what you think or if there is anything else i can do thanks!